An electrical motor comprising a rotor, a stator and additional components, which are situated in a housing of the electrical motor, are known from the German patent DE 195 23 789 A1. A plurality of stator windings on a stator core is located on said stator. Such a stator core is permanently affixed to the outer circumference of a carrying sleeve and consists of magnetic, respectively magnetizable, material. Furthermore, the rotor is permanently affixed to a shaft of the electrical motor. The control current is directed to the different stator windings on the armature of the stator via a control circuit in such a way that a rotating magnetic field arises in the interior of the motor. Said field then brings the rotor into rotation.
The electrical motor known from the German patent DE 195 23 789 A1 has the disadvantage that the plates and/or the plate assemblies are affixed onto the shaft in a complex way, which requires several job steps.
Rotors can be configured from one or a plurality of plate assemblies or from individual plates and additional components. The plates or plate assemblies are axially positioned onto the shaft, so that lie immediately adjacent to each other.
It is conceivable that the plates and/or plate assemblies could be affixed to the shaft by means of a cylindrical interference fit. In order that the forces do not increase too much when pressing the plate assemblies onto the shaft, the joining parts can have narrow tolerances. This, however, entails high manufacturing costs which are too expensive for many applications. In the case of connections where the joining can solely be produced by an interference fit, grooves result on the shaft and the plate assemblies from the high overlap during fitting. The form and the depth of the grooves have a high variance, whereby errors in the concentricity and an insufficiently large holding force occur in the assembled state. Moreover, these values can vary dramatically.
A solution is furthermore conceivable, wherein recesses or elevations are arranged on the shaft at the joint or the shaft is knurled at the joint. With regard to this solution, additional job steps for applying the recesses or knurling are necessary, and at the same time these methods are limited to a certain installation length. Where knurling is used to solve the task, the concentricity present after installation is not adequate for all applications. Furthermore, the danger exists when producing the recesses or the knurling, in particular in the case of a large length of the plate assemblies, that the shaft becomes uneven.
Solutions are furthermore conceivable, wherein the plates have recesses and/or elevations. When interference-fitting the plate assemblies, which have notched plates, onto the shaft, a fixed connection occurs at the joint location. In these embodiments a large error in the concentricity of a plate assembly, from which the rotor can be configured, to the shaft occurs because the recesses indefinitely deform and as a rule no additional space is present at the joint location, which produces the concentricity of the plate assembly to the shaft.